Feeding device for cold pilger mills

ABSTRACT

Feeding means for feeding stock to the dies of a cold pilger mill and the like, comprising a pair of feed carriages having the usual stock clamps, and means for moving the carriages in opposite directions on the machine bed in line with the dies. The clamps on the carriage moving toward the dies are engaged with the stock to feed the same, while the clamps of the carriage moving away from the stock are disengaged from the latter. Means are provided to move the carriages in increments, including a novel drive coordinated with crank shaft movement to feed the stock within a planned and predetermined crank range and variably adaptable to suit the quality and degree of deformation of the stock.

United States Patent Schmitt et al.

[ Sept. 5, 1972 [54] FEEDING DEVICE FOR COLD PILGER MILLS [72]Inventors: Paul Schmitt; Mnnifred Hien, both of Saarbruecken; Karl-HeinzKem merling, Moenchengladbach, all of Germany [73] Assignee: Wean1ndustries ,lnc., Yo1 1ngs tow1 ie W. 1

[22] Filed: Dec. 8, 1970 211 App]. No.: 96,042

[52] US. Cl ..226/141, 226/158 [51] Int. Cl. ..B65h 17/36 [58] Field ofSearch ..226/158, 159, 161, 162, 163,

226/l64,165,l66,l67, 141,139

[56] References Cited UNITED STATES PATENTS 2,389,556 11/1945 Siegerist..226/112 UX Ovshinsky ..226/ 162x lto ..226/112 ABSTRACT Feeding meansfor feeding stock to the dies of a cold pilger mill and the like,comprising a pair of feed carriages having the usual stock clamps, andmeans for moving the carriages in opposite directions on the machine bedin line with the dies. The clamps on the carriage moving toward the diesare engaged with the stock to feed the same, while the clamps of thecarriage moving away from the stock are disengaged from the latter.Means are provided to move the carriages in increments, including anovel drive coordinated with crank shaft movement to feed the stockwithin a planned and predetermined crank range and variably adaptable tosuit the quality and degree of deformation of the stock.

9Claims,6DrawingFigures PATENTED SEP 5 I972 sum 1 or 5 [HZ I L- l a*wcwi PAUL ScHMn'T KARp-HBNZ KEMMERLING MANI'FRED HE I ZMM/M/MPATENTEDSEP' 5 m2 3.688.962

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awe/Mow PAUL Sc H NWT KARL Hamz KEMMERUNG FEEDING DEVICE ron cow moanMILLS BACKGROUND AND SUMMARY In prior apparatus known to us, a lineshaft connects the crankshaft of the roll saddle with the feeding devicethrough bevel gear pairs and drives a pair of cams. These cams by meansof levers, supply the feeding movement for the feed carriage, and bymeans of worm gear sets supply the turning movement for the turningchucks. Since both cams are synchronized with the crankshaft, bothmovements occur simultaneously, and their time sequence repeats itselfperiodically.

Although these familiar types of drives proved successful in operation,there existed a need to simplify the mechanisms to increase the lifethereof, and our invention accomplishes these purposes.

According to our invention, the feeding device comprisesparallel-mounted feed spindles, each with a left and right hand thread,to move two feed carriages in opposite directions. The spindles aredriven through individual worm gear sets, both of which are connected byan extended worm shaft whose thread pitch is of corresponding size andhas leads in opposite directions. The turning of the worm gears iseffected by clutches that are alternately engaged and disengaged throughcontact switches cooperable with the feed carriages. The clutches arerotated through individual worm gear sets, the 'worm shaft of such setsimparting movement v DESCRIPTION OF THE DRAWINGS In the drawingaccompanying this specification and forming a part 'of this application,there is shown, for purpose of illustration, an embodiment which ourinvention may assume, and in these drawings:

FIG. 1 is a plan view of a cold pilger mill incorporating our invention,

FIG. 2 is a similar plan view drawn to slightly enlarged scale, andshowing the turning and feeding devices in section,

FIG. 3 is an enlarged, sectional view of the turning device,

FIG. 4 is a sectional view corresponding to the line 44 of FIG. 3,

FIG. '5 is an enlarged sectional view of the feeding device, and

FIG.- 6 is a fragmentary sectional view corresponding to the line 6-6 ofFIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 illustrate theinvention in general manner in a cold reduction 'mill installation. Amotor M, through belt 1 drives the crankshaft 2 of the roll saddle 3, inusual manner. The drive also causes rotation of a shaft 4 which isconnected to a work'tuming gear box 5 and a work feed gear 6, both gearboxes being located outside of the machine bed 7.

The gear boxes 5 and '6 cooperate with components mounted in housings 8and 9, respectively which operate to turn and feed the work. Thehousings 8 and 9 are located in the machine bed 7. A pair of feedcarriages 10, 11 are mounted on the machine bed for travel in oppositedirections through the medium of feed spindles l2 and 13.

The work turning gear box 5 may be of well known v construction and isshown herein only to complete the picture of the installation. As seenin FIGS. 3 and 4, the gear box 5 contains gearing which is driven by theshaft 4 to cause rotation of a shaft 14, the free end of which ismounted in bearings in the housing 8. The shaft 14 has a worm 14 whichmeshes with a pair of worm wheels 15, one 'of which is an idler wheeland the other of which transmits turning movement to chucks (not shownbut of familiar construction) which grip the work and rotate it as it'is being cold reduced by the pilger dies.

As is well known, the reducing dies 3a are carried by the roll saddle 3and the latter is reciprocated by the crank 2. The dies also roll alongthe workpiece to cold work the same and, as is customary, haveperipheral surfaces so contoured that the rolls engage the workpieceonly during a predetermined portion of a revolution of the crank, andare free of the workpiece during the remainder of the revolution of thecrank, so that a succeeding part of the workpiece may be fed for coldreduction by the dies.

The present invention utilizes the crankshaft drive 1 to feed thematerial to be rolled within a planned and predetermined crank range,and provides adjustment of 'the feed to suit the quality and degree ofdeformation of such material. For this purpose a cam 16 (FIG. 6) isfixed for rotation with the drive shaft 4, the cam being mounted in gearbox 6. The contour of the cam is so designed to fulfill. therequirements with regard to feeding within the crank angle assumedtherefore.

-A roller follower 17a is mounted for cooperation with the cam, thefollower being rotatably carried at one end of a lever 17. A slide 18carries the pivot 18a about which the lever 17 pivots. As seen in FIG.6, the

slide f8 is mounted within a slideway formed in the lever 17 and ismovable to various positions therein to thereby vary the amount ofmovement of the end 19 of the lever. The end 19 of the lever isconnected to a nonrotatable, longitudinally movable shaft 20.

One end of the shaft 20 is disposed within a coupling 21in a 'mannerwhereby the coupling may rotate relative to the shaft but also may bemoved in an axial direction by longitudinal movement of the shaft. The

opposite end of the shaft 20 is provided with a flange 29, and a spring30 is disposed between the flange and a portion of the housing 6 to urgethe shaft downwardly and thereby maintain the cam follower 17a incontact with the peripheral surface of the cam 16, and also to absorbshock which may be induced by longitudinal displacement of the shaft.

A spur gear 22-is mounted on the coupling 21 and engages with pinion 23mounted on a shaft 24 which is rotatably carried by the housing 6. Theshaft 24 has an 'end disposed outside of the housing and is driven by agear set 25 which, through another gear set 26, is connected-to a wormset 27 whose worm gear is mounted on drive shaft 4. Gear set 25 may bechanged so that feeding of the workpiece will always follow the timesequence which is mainly determined by the return movement of the rollerlever 17, as will later appear.

The rotatable coupling 21 is secured to one end of a shaft 31, theopposite end of the shaft having a pair of spaced worms 32a, 33a (FIG.5) fixed thereon. The womis mesh with respective worm gears 32, 33, andthe latter are disposed on shafts connected to one part of respectiveclutches 34, 35, The clutches are controlled through contacts cooperablewith respective feed carriages 10, 11, as will appear. The other partsof the clutches 34, 35 are connected to shafts on which worm gears 36,37 are fixed. The worm gears 36, 37 have opposite pitch directions,namely, right and left hand pitches, and are connected to respectivefeed spindles 12, 13 to rotate the same and thereby move the feedcarriages 10, 11.

Feed spindle 13 has one section 38 formed with a left hand screw threadand another section 39 formed with a right hand screw thread. The feedspindle 12 has one section 40 formed with a right hand thread andanother section 41 formed with a left hand thread.

For cold reducing a certain material, a certain feed rate is preset byadjustment of the slide 18 to provide a predetermined amount oflongitudinal movement of the shafts 20 and 31. Also, the gear set 25 ischosen to correspond to such longitudinal shaft movement.

The cam 16 is arranged on the shaft 4 in timed relation with a cycle ofthe crankshaft 2 so that the cam 16 begins to depress the cam follower17a shortly after the crankshaft has reached its portion of the cyclewherein the dies are no longer working on the workpiece and the latteris ready to be fed forwardly. As the shaft 4 rotates, the high portionof the cam 16, through the cam follower 17a, depresses the left hand endof lever 17 and therefore elevates the shafts 20 and 31 while the shaft31 is rotated by the drive consisting of the worm gear set 27, the gearset 26, the selected gear set 25, the pinion 23 and spur gear 22. Thespring 30 will absorb any shock caused by this movement and also willprevent separation between the cam follower and the cam.

Since the worms 32a, 33a are fixed to, or are an integral part of shaft31, these worms act in the manner of a gear rack to effect rotation ofthe respective worm gear 32, 33, and this is cumulative with therotation of the shaft 31 by the rotating drive.

The turning of the worm gears 32,33 is translated to the respectiveparts of clutches 34, 35. Assuming clutch 35 is disengaged and clutch 34is engaged, worm gear 37 is rotated in the same direction (clockwise forexample) as worm gears 32, 33, and therefore spindle 12 is also rotatedin this direction. The worm shaft on which worms 36a, 37a are fixed isalso rotated in a clockwise direction by reason of the meshing of worm37awith worm gear 37. However, the worm 36a and its gear 36 are of apitch opposite to that of the worm 37a and worm gear 37 and thereforethe worm gear 36 is rotated in a counterclockwise direction. Therefore,the two feed spindles .12, 13 are rotated in opposite directions.

Since the spindle 12 has portions 40, 41 of right and left hand threadswhich are threaded in nuts which are respectively carried by the feedcarriages 10, 11, and spindle 13 has portions 38, 39 of left and righthand threads which are threaded in nuts respectively carried by the feedcarriages 10, 11, the latter are caused to move in opposite directions.Accordingly, when the carriage moves in a direction toward the dies, its

clamp jaws are engaged with the workpiece to feed it in a directiontoward the rocking dies 3a. At the same time, the carriage 11 will bemoved in an opposite direction, and its clamp jaws will be open so asnot grip the workpiece.

After the cam 16 has been rotated so that its high point passes the camfollower 170, the feeding effect of the worms 32a, 33a ceases since theshaft 31 is not longer moved in an upward direction, referring to theposition of parts in FIG. 5. The feed carriages 10, 11 therefore nolonger move and the rotation of the shaft 31 is not able to overcome theweight of the slides and friction in the worm gear sets, so the wormgears 32, 33 at this time remain stationary and the rotation of theshafts causes the worms 32a, 33a to screw themselves out of therespective worm gears 32, 33 and thereby move the shaft 31 downwardly(with respect to FIG. 5). The change gear set 25 has been chosen so thatit imparts rotation to the shaft 31 in the precise amount necessary tomaintain the cam follower 17a in engagement with the cam periphery asthe worms 32a, 33a unscrew themselves out of the worm gears 32, 33.Thus, the carriages l0, 11 are moved in increments depending upon theadjusted position of the pivot 18a, and this adjustment may be madeoutside of the machine frame and outside of the gear box 6. The gear set25 may also be easily changed since this set is located outside the gearbox 6.

When the feed carriages 10, 11 have been incrementally moved apredetermined amount, as when the carriage 10 is moved to apredetermined limit in a direction toward the rocking dies, the carriage10 will engage a limit switch 40 (see FIG. 1) to disengage the clutch 34and engage the clutch 35, whereupon the drive caused by the rack effectof the worms 32a, 33a will be translated to the worm gear 36 and thespindles 12, 13 will be driven in reverse but opposite directions.Therefore, the carriage 10 will be moved in a direction away from therocking dies 30 and its clamping jaws will be open. At the same time,the carriage 11 will be moved in a direction toward the rocking dies andits clamping jaws will be closed on the work to thereby feed theworkpiece toward the dies. After a predetermined amount of carriagemovement, the carriage 10 may engage another limit switch 41 (seeFIG. 1) whereupon the clutch 35 is disengaged and the clutch 34 againengaged to cause feeding of the workpiece by means of the carriage 10.

We claim:

1. Mechanism for feeding stock to the dies of a cold pilger mill,comprising a pair of feed carriages mounted on the frame of the mill formovement toward and away from the dies, with the jaws of the carriagemoving toward the dies being closed on the stock and the jaws of thecarriage moving away from the dies being disengaged from the stock,means for moving said carriages in opposite directions comprising a pairof parallel,

rotatably mounted feed spindles, one feed spindle having left hand screwconnection with one carriage and a right hand screw thread connectionwith the other carriage, and the other feed spindle having a right handscrew connection with said one carriage and a left hand screw threadconnection with said other carriage, and means for rotating saidspindles in opposite directions.

2. The construction according to claim 1 wherein said feed spindles arerotated by two double worm gear sets, the worm gears of such sets beingcontrollably connected by a pair of clutches, means including the wormsof one set for rotating the worm gears of said one set in apredetermined direction, and means controlling operation of saidclutches to drivingly engage one or the other worm gear of the other setwith the worm gears of said one set, said one or the other worm gearsbeing of opposite pitch and meshing with corresponding worms which aretied together for rotation, the driven one of said other worm gearsdriving the other through said corresponding worms, and said other wormgears driving the other through said corresponding worms, in said otherworm gears being in driving relation with respective feed spindles.

3. The construction of claim 2 wherein the worms of said one gear setare on a common shaft which is movable axially so that said worms rotatetheir respective worm gears through a rack effect.

4. The construction according to claim 3 wherein said common shaft ismoved axially by connection with one end of a lever, the opposite endhaving a follower engaging a cam which is rotated by a rotatable shafthaving driven connection with the drive for the crankshaft of said dies.

5. The construction according to claim 4 wherein the pivot of said leveris shiftable between the lever ends to thereby vary the amount of axialmovement of said common shaft.

6. The construction according to claim 5 wherein said common shaft isalso rotated by a train of gears which are drivenby connection with theshaft that rotates said cam.

7. The construction according to claim 6 wherein said train of gearsincludes a set of change gears whereby said set may be interchanged withanother set to vary the speed of rotation of said common shaft.

8. The construction according to claim 7 wherein a different change gearset is included in said train of gears each time said pivot of saidlever is shifted to another position, the selected change gear setbearing direct relation to the amount of axial movement of said commonshaft.

9. A feeding device for cold pilger mills having a reciprocating rollsaddle, the main drive of said mill being drivingly connected withseparate gear boxes outside of the machine bed to furnish a feed andturn movement for the stock through clamping carriages and clampingjaws, said feed device being characterized by a reversing gear set of atype where through two double worm gear sets and two clutches twoparallel feed spindles are driven, each feed spindle having threadedsections of opposite pitch, each section being I connected in threadedfashion to a clamping carriage.

1. Mechanism for feeding stock to the dies of a cold pilger mill,comprising a pair of feed carriages mounted on the frame of the mill formovement toward and away from the dies, with the jaws of the carriagemoving toward the dies being closed on the stock and the jaws of thecarriage moving away from the dies being disengaged from the stock,means for moving said carriages in opposite directions comprising a pairof parallel, rotatably mounted feed spindles, one feed spindle havingleft hand screw connection with one carriage and a right hand screwthread connection with the other carriage, and the other feed spindlehaving a right hand screw connection with said one carriage and a lefthand screw thread connection with said other carriage, and means forrotating said spindles in opposite directions.
 2. The constructionaccording to claim 1 wherein said feed spindles are rotated by twodouble worm gear sets, the worm gears of such sets being controllablyconnected by a pair of clutches, means including the worms of one setfor rotating the worm gears of said one set in a predetermineddirection, and means controlling operation of said clutches to drivinglyengage one or the other worm gear of the other set with the worm gearsof said one set, said one or the other worm gears being of oppositepitch and meshing with corresponding worms which are tied together forrotation, the driven one of said other worm gears driving the otherthrough said corresponding worms, and said other worm gears driving theother through said corresponding worms, in said other worm gears beingin driving relation with respective feed spindles.
 3. The constructionof claim 2 wherein the worms of said one gear set are on a common shaftwhich is movable axially so that said worms rotate their respective wormgears through a rack effect.
 4. The construction according to claim 3wherein said common shaft is moved axially by connection with one end ofa lever, the opposite end having a follower engaging a cam which isrotated by a rotatable shaft having driven connection with the drive forthe crankshaft of said dies.
 5. The construction according to claim 4wherein the pivot of said lever is shiftable between the lever ends tothereby vary the amount of axial movement of said common shaft.
 6. Theconstruction according to claim 5 wherein said common shaft is alsOrotated by a train of gears which are drivenby connection with the shaftthat rotates said cam.
 7. The construction according to claim 6 whereinsaid train of gears includes a set of change gears whereby said set maybe interchanged with another set to vary the speed of rotation of saidcommon shaft.
 8. The construction according to claim 7 wherein adifferent change gear set is included in said train of gears each timesaid pivot of said lever is shifted to another position, the selectedchange gear set bearing direct relation to the amount of axial movementof said common shaft.
 9. A feeding device for cold pilger mills having areciprocating roll saddle, the main drive of said mill being drivinglyconnected with separate gear boxes outside of the machine bed to furnisha feed and turn movement for the stock through clamping carriages andclamping jaws, said feed device being characterized by a reversing gearset of a type where through two double worm gear sets and two clutchestwo parallel feed spindles are driven, each feed spindle having threadedsections of opposite pitch, each section being connected in threadedfashion to a clamping carriage.